Crypt Function-- Encryption and Decryption

Hi All, I have a password file , which has all the passwords words encrypted with the Crypt Function I know that Crypt uses one-way algorithm to generate the encryptions and PHP has no Decrypt function , ( but can it be developed to have one ?) But I am eager to know whether it is really impossible to decrypt the passwords , if possible , how it caqn be done. like salts and all Can somebody *please* throw more light on Crypt() and Encryption and Decryption in this thread. Thanks, Nikhil